title: Variability of nursing care by APR-DRG and by severity of illness in a sample of nine Belgian hospitals.
abstract: BACKGROUND
  As soon as Diagnosis related Groups (DRG) were introduced in many hospital financing systems, most nursing research revealed that DRG were not very homogeneous with regard to nursing care. However, few studies are based on All Patient refined Diagnosis related Groups (APR-DRGs) and few of them use recent data. Objectives of this study are: (1) to evaluate if nursing activity is homogeneous by APR-DRG and by severity of illness (SOI) (2) to evaluate the outlier's rate associated with the nursing activity and (3) to compare nursing cost homogeneity per DRG and SOI.
  
  
  METHODS
  Study done in 9 Belgian hospitals on a selection of APR-DRG with more than 30 patients (7 638 inpatient stays). The evaluation of the homogeneity is based on coefficients of variation (CV). The 75th percentile + 1.5 × inter-quartile range was used to select high outliers. 25th percentile -1.5 × inter-quartile range was used to select low outliers. Nursing costs per ward were distributed on inpatient stays of each ward following two techniques (the LOS vs. the number of nursing care minutes per stay).
  
  
  RESULTS
  The homogeneity of LOS by DRG and by SOI is relatively good (CV: 0.56). The homogeneity of the nursing activity by DRG is less good (CVs between 0.36 and 1.54) and is influenced by nursing activity outliers (high outliers' rate: 5.19%, low outliers' rate: 0.14%). The outlier's rate varies according to the studied variable. The high outliers' rate is higher for nursing activity than for LOS. The homogeneity of nursing costs is higher when costs are based on the LOS of patients than when based on minutes of nursing care (CVs between 0.26 and 1.46 for nursing costs based on LOS and between 0.49 and 2.04 for nursing costs based on minutes of nursing care).
  
  
  CONCLUSIONS
  It is essential that the calculation of nursing cost by stay and by DRG for hospital financing purposes was based on nursing activity data, that more reflect resources used in wards, and not on LOS data. The only way to obtain this information is the generalization of computerized nursing files.
authors.affiliation: Health Economics, Hospital's Management and Nursing research Department, CP592- School of Public Health, Université Libre de Bruxelles, 808, Route de Lennik, B- 1070, Bruxelles, Belgium. magali.pirson@ulb.ac.be.
authors.forename: Magali
authors.initials: M
authors.lastname: Pirson
authors.forename: Caroline
authors.initials: C
authors.lastname: Delo
authors.forename: Lionel
authors.initials: L
authors.lastname: Di Pierdomenico
authors.forename: Nancy
authors.initials: N
authors.lastname: Laport
authors.forename: Veronique
authors.initials: V
authors.lastname: Biloque
authors.forename: Pol
authors.initials: P
authors.lastname: Leclercq